gsrlabs/go
1
0
Fork 0
mirror of https://github.com/golang/go.git synced 2026-01-31 08:02:06 +03:00
Code Issues Packages Projects Releases Wiki Activity

cmd/compile: remove 68857 ModU flowLimit workaround in prove

Browse Source 
We can know this is correct because all the testcases added by CL 605156 are still passing.
Partial revert of CL 605156 (everything but the testcases).

Change-Id: I5d8daadb4cb35a9de29daaabc22baee642511fe0
Reviewed-on: https://go-review.googlesource.com/c/go/+/714941
Reviewed-by: Keith Randall <khr@google.com>
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Jorropo <jorropo.pgm@gmail.com>
Reviewed-by: Keith Randall <khr@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
This commit is contained in:
Jorropo
2025-10-25 18:38:23 +02:00
committed by Gopher Robot
parent a50de4bda7
commit 2ce5aab79e
1 changed files with 8 additions and 13 deletions
Download Patch File Download Diff File Expand all files Collapse all files

21
src/cmd/compile/internal/ssa/prove.go
View File

@@ -1962,19 +1962,6 @@ func (ft *factsTable) flowLimit(v *Value) bool {
b := ft.limits[v.Args[1].ID]
bitsize := uint(v.Type.Size()) * 8
return ft.newLimit(v, a.mul(b.exp2(bitsize), bitsize))
case OpMod64, OpMod32, OpMod16, OpMod8:
a := ft.limits[v.Args[0].ID]
b := ft.limits[v.Args[1].ID]
if !(a.nonnegative() && b.nonnegative()) {
// TODO: we could handle signed limits but I didn't bother.
break
}
fallthrough
case OpMod64u, OpMod32u, OpMod16u, OpMod8u:
a := ft.limits[v.Args[0].ID]
b := ft.limits[v.Args[1].ID]
// Underflow in the arithmetic below is ok, it gives to MaxUint64 which does nothing to the limit.
return ft.unsignedMax(v, min(a.umax, b.umax-1))
case OpDiv64, OpDiv32, OpDiv16, OpDiv8:
a := ft.limits[v.Args[0].ID]
b := ft.limits[v.Args[1].ID]
@@ -2484,6 +2471,14 @@ func addLocalFacts(ft *factsTable, b *Block) {
OpRsh32Ux64, OpRsh32Ux32, OpRsh32Ux16, OpRsh32Ux8,
OpRsh64Ux64, OpRsh64Ux32, OpRsh64Ux16, OpRsh64Ux8:
ft.update(b, v, v.Args[0], unsigned, lt|eq)
case OpMod64, OpMod32, OpMod16, OpMod8:
a := ft.limits[v.Args[0].ID]
b := ft.limits[v.Args[1].ID]
if !(a.nonnegative() && b.nonnegative()) {
// TODO: we could handle signed limits but I didn't bother.
break
}
fallthrough
case OpMod64u, OpMod32u, OpMod16u, OpMod8u:
ft.update(b, v, v.Args[0], unsigned, lt|eq)
// Note: we have to be careful that this doesn't imply